The present application is concerned with a spread containing less than 35 wt.% fat, comprising from 10 to 35 wt.% continuous fat phase and from 90 to 65 wt.% dispersed aqueous phase.
Water-in-oil spreads that can be used as replacement for butter or margarine, having a fat content below 80 wt.%, are well known. A wide variety of such products is commercially available. Most of these products have a fat content of about 40 wt.%.
There is, however, a need for spreads comprising a continuous fat phase and a dispersed aqueous phase having a fat content of substantially less than 40 wt.%.
A spread should have a plastified continuous fat phase to give it suitable spreadability and to prevent microbiological deterioration. It should not release moisture when it is being spread. Furthermore, a spread should be spreadable at refrigerator temperature, be stable at room temperature, but destabilize and release its flavour in the mouth. These goals are very difficult to achieve if only a small amount of fat is to be used to constitute the continuous phase.
In GB 2,035,360 a process is disclosed for the preparation of water-in-oil spreads containing 20 wt.% fat. According to this process, the aqueous phase is sprayed onto the fatty phase. During the addition of the sprayed aqueous phase, the emulsion is circulated through a static mixer to increase the viscosity. The final viscosity suitably is about 18000 mPa.s at a shear rate of 13 sec..sup.-1 and 2700 mPa.s at a shear rate of 134 sec..sup.-1 at 38.degree. C. When this viscosity has been obtained, the emulsion is cooled and worked to cause crystallization of fat to occur.
In practice, this process has not been successful. It is difficult to apply the process under factory conditions and the products obtained tend to be too stable in the mouth, which results in an insufficient release of flavour from the aqueous phase droplets.
EP 0 011 344 teaches to incorporate in fat-continuous spreads containing 18-82 wt.% fat phase, a gelled aqueous phase having a softening point of at least 33.degree. C., showing a sharp decrease in gel strength at a temperature ranging from 45.degree. to 70.degree. C. and a gel strength at a temperature below the softening point ranging from 0.1 to 30 N/cm.sup.2. The gelling agents to be used according to EP 0 011 344 are of the medium-melting type. The specification warns against using low-melting type gelling agents, e.g. gelatin, of which is said that they are often more difficult to process and may result in products of too sticky a mouthfeel or in too watery products. Spreads having very low fat contents, prepared with aqueous phase compositions as disclosed in EP 0 011 344 have been found to be unsatisfactory. In particular, such spreads tend to release water under spreading conditions.
U.S. Pat. No. 4,536,408 describes low-fat spreads comprising 15-35 wt.% fat and 15-35 wt.% of a non-gelling starch hydrolyzate having a DE (dextrose equivalent) of 4-25. The products are prepared by cooling and mixing the fat into an aqueous solution of the starch hydrolyzate with a high-speed blender, until phase inversion occurs. The products disclosed in U.S. Pat. No. 4,536,408 have been found to have a poor oral response. They do not break down sufficiently in the mouth and, consequently, they have a poor flavour release.